package com.atguigu.sh.juc;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * ThreadOrderAccess
 * 题目：多线程之间按顺序调用，实现A->B->C
 * 三个线程启动，要求如下：
 * AA打印5次，BB打印10次，CC打印15次
 * 接着
 * AA打印5次，BB打印10次，CC打印15次
 * 来10轮
 *      1.高内聚低耦合前提下，线程操作资源类
 *      2.判断/干活/通知
 *      3.多线程交互中，防止虚假唤醒(判断只能用while，不能用if)
 *      4.标志位
 * @author daixl
 * @date 2021/6/15
 */
public class ThreadOrderAccess {

    public static void main(String[] args) {
        ShareResource shareResource = new ShareResource();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                shareResource.print5();
            }
        }, "A").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                shareResource.print10();
            }
        }, "B").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                shareResource.print15();
            }
        }, "C").start();
    }
}

/**
 * 资源类
 */
class ShareResource{

    private int number = 1; //1:A   2:B    3:C
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();

    public void print5(){
        lock.lock();
        try {
            //1.判断
            while (number != 1){
                condition1.await();
            }
            //2.干活
            for (int i = 0; i < 5; i++) {
                System.out.println(Thread.currentThread().getName() + "\t" + "A");
            }
            //3.通知
            number = 2;
            condition2.signal();
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("失败啦");
        } finally {
            lock.unlock();
        }
    }

    public void print10(){
        lock.lock();
        try {
            //1.判断
            while (number != 2){
                condition2.await();
            }
            //2.干活
            for (int i = 0; i < 10; i++) {
                System.out.println(Thread.currentThread().getName() + "\t" + "B");
            }
            //3.通知
            number = 3;
            condition3.signal();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public void print15(){
        lock.lock();
        try {
            //1.判断
            while (number != 3){
                condition3.await();
            }
            //2.干活
            for (int i = 0; i < 15; i++) {
                System.out.println(Thread.currentThread().getName() + "\t" + "C");
            }
            //3.通知
            number = 1;
            condition1.signal();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
}
